Lamp stem making machine



Dec. 23, 1941. I R. B. THOMAS LAMP STEM MAKING MACHINE 4 Sheets-Sheet 1 Filed Nov. 20, 1940 Dec. 23, 19.41. R. B. THOMAS LAMP STEM MAKING MACHINE 4 Sheets- Sheet 2 llflllllllllIIIIIIIIIIIIIzAI/I Filed Nov. 20, 1940 Ral h ,E. T100751? Dec. 23, 1941. R. B. THOMAS LAMP YSTEM MAKING MACHINE 4 Sheets-Sheet a Filed Nov. 20, 1940 K E I T INVENTOR.

QQW n... flwrmg De c. 23, 1941. R. B. THOMAS LAMP sum MAKING MACHINE Filed Nov'. 20, 1940 4 Sheets-Sheet 4 7&1 l bh B. Thomas, INVENTOR.

- ATTORNEY I Patented Dec. 23, 1941 UNITED r STATES PATENT OFFICE, 7

LAMP STEM MAKING MACHINE Ralph B. Thomas, Beverly, Mass. minor to Hygrade Sylvania Corporation, Salem, Mass, a corporation of Massachusetts Application November 20, 1940, Serial No. 366,428

Jecting downwardly from the top portion thereof.

3 Claims.

This invention relates to electric lamps and more particularly to a stem machine for fluorescent lamps.

An object of this invention is to provide a stem machine head which will provide for the admittance of air under controlled pressure to the in-.

side oi. the exhaust tube to blow out the exhaust port.

Another object is to provide a stem machine head which will provide for the admittance of air section of the stem head assembly;

Figure 2 is a detail shown partly in section of the exhaust tubing-chuck and the telescoping air channels;

Figure 3 is a detail, shown in section of the exhaust tubing chuck;

Figure 4 is a bottom plan view of the exhaust tubing chuck;

Figure 5 is a detail shown in section of the stem swelling nozzles and the exhaust tubing air channels;

Figure 6 is a plan view of the stem machine;

Figure 7 is a side elevational view shown partly in section of the stem head assembly.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

The stem usually used in fluorescent lamps is a distinct type. .Although similar in diameter dimension to a regular 60 watt incandescent lamp stem, it is not as long, and it is preferably without a stem press because of the short throat of the flare. Standard incandescent methods of positioning the parts assembly, 1. e., the flare, the exhaust tube and the lead wires may be employed. However, I have found that distinct advantages may be obtained by inverting these f parts. Hence a special stem machine head is necessary.

In Figure l, the head frame I is mounted on the pulley shaft H to which the head pulley 26 is attached. The head frame I serves as the frame on which the stem head assembly is mounted. This head frame I is substantially The flare guide jaw assemblies l6 are pivotally mounted on the pins 28 through the stud 50 which project down from the top portion of the rectangular head frame I. Thus when it is desired to cause these jaw assemblies to open in order to permit the insertion of the flare i3, the exhaust tubing l5 and the lead wire it into their respective positions. the operator of the machine presses the finger lever 2| in a downward direction. By pressing the finger lever 24 downward, the pivotal frame finger 23 attached thereto will push downward on the pivotal frame baflle 22 mounted on the pivotal frame. 2 I. The connecting rods join the flare guide jaw assemblies I6 and the pivotal framebaille 22 mounted on the pivotal frame 2| which is firmly attached to the lower sleeve holder 6 through the setscrews 5 I. The connecting rods 20 join the flare guide jaw assemblies l8 and the pivotal frame 2| so that when the pivotal frame 2| moves downward, the jaw assemblies I6 pivoting on the pins 28, will be drawn downward by the connecting rods 20, thus opening the jaws for the insertion of the lead-in wires, the flare and the exhaust tube in their proper positions.

The lower sleeve 5 telescopes within the mount pin sleeve 3, and is attached at its lower extention.

law assemblies I! are the flare guides 1 and the a sion tov the lower sleeve holder 6 which in turn extends down through the pivotal frame 2| and through the bottom of the head frame I in a piston like manner. Thus the lower sleeve 5 is drawn downward when the jaw assemblies it are opened by reason-of the fact that the lower sleeve holder 6 is attached to the downwardly moving pivotal frame 2i. The pivotal frame spring 25 encircles the lower sleeve holder 6 between the bottom of the pivotal frame 2| and the lower extension of the head frame I.

Mounted on top of the flare guide jaw assemblies I8 are the upper support rods ill for the W guides 9 which hold the lead wires in posi- Also mounted 'on top of the flare guide heat deflectors 8. These baliles l and 8 encircle the flare and help to hold it in place.

As has been pointed out above, air pressure is employed not only to blow out a vent in the stem press but also to-swell the stem. If it is desired to keep open at all times the end of the exhaust tube l5, located within the throat of the flare I3 as shown 1 Figure 1, then air must be caused to be blown up through the exhaust'tube at substantially all of the positions to which the head lar in shape and has the studs it pro- 66 indexes as shown in Figure 6. If on the other frame i.

hand, it is desired to first permit the throat of the flare l3 to'become melted in as shown in Figure 7, and then blow a. vent out through the molten glass, this may also be done by simply refraining from causing any air to be forced up through the exhaust tube E5 until the head has indexed to a position where the throat of the flare has been melted in to the desired extent.

l'he purpose of the admission of air to swell the throat of the flare is to prevent the glass from sagging downward when softened by the heat. If the throat of the flare were melted in and the softened glass permitted to take whatever form it desired, uniformity of contour of this mass of melted glass would be impossible. Not only does the stem swelling accomplish a control over the formation of the stem, but it also stretches and swells the stem while the glass is still in a molten state thus diminishing the strains and reducing the danger of having the glassy crack. This working of the molten glass is thus entirely automatic in any stem machine head. The manner in which air pressure is obtained to accomplish these two ends is illustrated in Figures 1, 5 and i. The stem swelling air inlet pipe ll extends down from the top of the head frame i and enters the bottom of the head frame at a point slightly above where the head frame joins the pulley shaft H, The vent d5, located'in the pulley shaft ll, provides the opening through which the stem swelling air inlet pipe is connected to the channel 36 in the machine turret 273. The chamber 4? formed by the turret 21 and the shaft H adjacent the vent 55 provides for the continuous flow of air through the channel 86 into the vent &5 even while the head is rotating. This air is introduced into the stem swelling air inlet pipe through the channel in the turret and the vent in the pulley shaft. The air line 30 for conducting air to blow out a vent in the stem is shown in phantom in Figure l as running from the bottom of the head pulley up through the pulley shaft ii, the lower sleeve holder 5 and the lower sleeve 5. Thu the air coming up the air line 30 passes through the shoulder 3! of the lower sleeve 5 and into the lower end of the exhaust tube I5 so that it may keep the upper end'of the tube I! open while the stem 48; as shown'infigure 7 is being formed.

Figure 5 shows in detail just how these air passages accomplish their purpose. The air comes up through'the inlet pipe l7 located in the head The air is evenly distributed to the stem swelling air nozzles l8 through the annular air ring 29. The flare is positioned on the flare seat i2 through which the stem swelling air nozzles extend. This figure also shows the location of the slots l9 into which the lead-in wires are placed. These slots H are located inthe mount pin 2 in the top of the head frame i. The exhaust tube chuck l and the mount pin sleeve 3 are held within the mount pin 2.

Figure 2 shows the exhaust tube chuck and the telescoping air channels. It shows how the exhaust tube chuck 4, the lower sleeve 5 and the lower sleeve holder 6 cooperate with the flare guide jaw assemblies l6 when these jaws are opened for the positioning of the exhaust tube, the lead-in wires and the flare. This flgure shows the lower sleeve 5 and the lower sleeve holder 6 in their downward position, having I been drawn down by reason of being attached to the pivotal frame 2| which is pushed downward through the finger lever 2|. The exhaust tube I5 is shown on its way down through the exhaust accuses tube chuck ll. It will drop or may be pushed down still further until its lower extremity is resting on the shoulder Si of the lower sleeve 5. when thevarious parts have been properly positioned, the finger lever is released and the jaw assemblies 66, with the W guides thereon, will close in on the flare and the lead wires, holding them firmly in position as shown in Figure 1 while the lower sleeve 5 will slide up inside themount pin sleeve 3 as shown. in Figure 2, until the cone-like portion of the lower sleeve 5 has encircled the jaws of the exhaust tube chuck t, thus causing the mount chuck to firmly grip thev exhaust tube 55. These jaws on the mount chuck are flexible enough to be sensitive to the cone-like portion of the lower sleeve so that the gripping of the exhaust tubing may be accomplished. The efiaust tubing 55 rides up with the lower sleeve 5 until the cone-like portion of the sleeve 5 encircles the jaws of the chuck i. The length of theexhaust tubing and the distance which it rides up with the sleeve 5 is so calculated as to result in the location of the top part of the exhaust tubing in the desired position in relation to the flare Figure 6 shows a stem machine on which a head of this typemay be used. The machine turret 21 may be mounted on the table 33. The annealingflres 3b, the melting fires 3i and the air cooling nozzles 38 are connected through the stationary turret bearing 39 about which the machine turret 27 indexes. The stem swelling air ducts 32 project from the pulley shafts l l and are flexible so that they may establish connecnection with air inlets located beneath the melting fires 3?, thus providing a source of air for the stem swelling air inlet pipe ll, as shown in Figure 1. The source of air for blowing out the exhaust vent in the stem may be located directly beneath the shafts i E. I have purposely shown Figure 6 without the heads, described above, mounted in their positions for the sake of clarity in the drawing. Each head is kept continuously rotating, from the time the stem assembly parts have been loaded on the machine until it is time to remove the finished stem. This is accomplished by reason of the continuous motion of the belt' 3d being guided about the belt idler pulleys 35 to a suitable drive and thus turning the head pulleys 26.

If it is desired to make a stem without an exhaust tube therein, it may be very readily made on this machine by merely closing off the air through the exhaust tube blowing-out chan- 118139.

What I claim is:

1. A head for an electric lamp stem making machine in which a flare, lead wires and an exhaust tube are sealed together, said head comprising: a seat for said flare; means for positioning said lead wires; means for positioning said exhaust tube; means for blowing out a vent from the exhaust tube through the throat of the flare; and separate means for swelling said stem.

2. A head for an electric lamp stem making machine in which a flare, lead wires and an exhaust tube are sealed together, said head comprising: a seat for said flare; jaws for locking said flare in said seat; means for locating the lead wires in their extension through the flare; means for holding the exhaust tube in a position to have one end within the throat of the flare; means for blowing out a. vent from the exhaust tube means for swelling said flare.

3. A head for an electric lamp stem making machine in which a flare, lead wires and an exhaust tube are sealed together by melting the glass flare and glass exhausttube, said head comprising: a seat for said flare; means for locating the lead wires in their extension through the flare; jaws for locking said flare in said seat, said jaws being pivotally mounted to provide for the insertion and withdrawal of the flare from the locking position on said seat and having the means for locating the lead wires mounted thereon; means for holding the exhaust tube in a position to have one end within the throat of the flare; means for blowing out a vent from the exhaust tube through the throat of the flare, and separate means for swelling said flare through apertures in the seat for the flare.

- RALPH B. THOMAS. 

